Support RelayPacket in Auth and World servers.

Author: masterking32

src/server/authserver/Server/AuthSession.cpp

@@ -25,6 +25,7 @@
 #include "CryptoRandom.h"
 #include "DatabaseEnv.h"
 #include "IPLocation.h"
+#include "IpAddress.h"
 #include "Log.h"
 #include "RealmList.h"
 #include "SecretMgr.h"
@@ -45,7 +46,8 @@ enum eAuthCmd
     XFER_DATA = 0x31,
     XFER_ACCEPT = 0x32,
     XFER_RESUME = 0x33,
-    XFER_CANCEL = 0x34
+    XFER_CANCEL = 0x34,
+    RELAY_PACKET = 0x64 // Relay packet from relay server to auth server according to the https://github.com/masterking32/WoW-Server-Relay
 };
 
 #pragma pack(push, 1)
@@ -110,6 +112,16 @@ typedef struct AUTH_RECONNECT_PROOF_C
 } sAuthReconnectProof_C;
 static_assert(sizeof(sAuthReconnectProof_C) == (1 + 16 + 20 + 20 + 1));
 
+typedef struct RELAY_PACKET_C
+{
+    uint8    cmd;
+    uint16   secret_len;
+    uint16   ip_len;
+    uint8    secret[1];
+    uint8    ip[1];
+} sRelayPacket_C;
+static_assert(sizeof(sRelayPacket_C) == (1 + 2 + 2 + 1 + 1)); // 1 byte for the cmd, 2 bytes for the secret length, 2 bytes for the IP length
+
 #pragma pack(pop)
 
 std::array<uint8, 16> VersionChallenge = { { 0xBA, 0xA3, 0x1E, 0x99, 0xA0, 0x0B, 0x21, 0x57, 0xFC, 0x37, 0x3F, 0xB3, 0x69, 0xCD, 0xD2, 0xF1 } };
@@ -119,10 +131,13 @@ std::array<uint8, 16> VersionChallenge = { { 0xBA, 0xA3, 0x1E, 0x99, 0xA0, 0x0B,
 #define AUTH_LOGON_CHALLENGE_INITIAL_SIZE 4
 #define REALM_LIST_PACKET_SIZE 5
 
+#define MAX_RELAY_PACKET_SIZE (sizeof(RELAY_PACKET_C) + 64 + 46) // 64 bytes for the secret, 46 bytes for the IP address (Even though IPv6 is 39 bytes, we use 46 bytes to be safe)
+
 std::unordered_map<uint8, AuthHandler> AuthSession::InitHandlers()
 {
     std::unordered_map<uint8, AuthHandler> handlers;
 
+    handlers[RELAY_PACKET]             = { STATUS_CHALLENGE,    sizeof(RELAY_PACKET_C),            &AuthSession::HandleRelayPacket };
     handlers[AUTH_LOGON_CHALLENGE]     = { STATUS_CHALLENGE, AUTH_LOGON_CHALLENGE_INITIAL_SIZE, &AuthSession::HandleLogonChallenge };
     handlers[AUTH_LOGON_PROOF]         = { STATUS_LOGON_PROOF, sizeof(AUTH_LOGON_PROOF_C),        &AuthSession::HandleLogonProof };
     handlers[AUTH_RECONNECT_CHALLENGE] = { STATUS_CHALLENGE, AUTH_LOGON_CHALLENGE_INITIAL_SIZE, &AuthSession::HandleReconnectChallenge };
@@ -243,6 +258,15 @@ void AuthSession::ReadHandler()
                 CloseSocket();
                 return;
             }
+        } else if (cmd == RELAY_PACKET)
+        {
+            sRelayPacket_C* relayPacket = reinterpret_cast<sRelayPacket_C*>(packet.GetReadPointer());
+            size += relayPacket->secret_len + relayPacket->ip_len - 2; // -2 because the secret and IP lengths are already included in the size
+            if (size > MAX_RELAY_PACKET_SIZE)
+            {
+                CloseSocket();
+                return;
+            }
         }
 
         if (packet.GetActiveSize() < size)
@@ -273,6 +297,71 @@ void AuthSession::SendPacket(ByteBuffer& packet)
     }
 }
 
+bool AuthSession::HandleRelayPacket()
+{
+    sRelayPacket_C* relayPacket = reinterpret_cast<sRelayPacket_C*>(GetReadBuffer().GetReadPointer());
+
+    if (relayPacket->secret_len > 64 || relayPacket->ip_len > 46)
+    {
+        TC_LOG_DEBUG("server.authserver", "[RelayPacket] Relay packet is too large");
+        _status = STATUS_CLOSED; // Close the connection if the packet is too large
+        return false;
+    }
+
+    if (relayPacket->secret_len < 1 || relayPacket->ip_len < 1)
+    {
+        TC_LOG_DEBUG("server.authserver", "[RelayPacket] Relay packet is too small");
+        _status = STATUS_CLOSED; // Close the connection if the packet is too small
+        return false;
+    }
+
+    std::string secret(reinterpret_cast<char const*>(relayPacket->secret), relayPacket->secret_len);
+    std::string ip(reinterpret_cast<char const*>(relayPacket->secret + relayPacket->secret_len), relayPacket->ip_len);
+    std::string configSecretKey = sConfigMgr->GetStringDefault("RelayServerSecret", "secret");
+
+    if(configSecretKey.empty() || configSecretKey == "secret")
+    {
+        TC_LOG_ERROR("server.authserver", "[RelayPacket] Relay server secret is not set or is default. Please set a unique secret key with a maximum of 64 characters in the authserver.conf configuration file.");
+        _status = STATUS_CLOSED; // Close the connection if the secret is not set
+        return false;
+    }
+
+    if (secret != configSecretKey)
+    {
+        TC_LOG_DEBUG("server.authserver", "[RelayPacket] Invalid secret");
+        _status = STATUS_CLOSED; // Close the connection if the secret is invalid
+        return false;
+    }
+
+    if (ip.empty())
+    {
+        TC_LOG_DEBUG("server.authserver", "[RelayPacket] IP is empty");
+        _status = STATUS_CLOSED; // Close the connection if the IP is empty
+        return false;
+    }
+
+    boost::system::error_code ip_error;
+    boost::asio::ip::address ip_address = Trinity::Net::make_address(ip, ip_error);
+    if (ip_error)
+    {
+        TC_LOG_DEBUG("server.authserver", "[RelayPacket] Invalid IP '{}'", ip);
+        _status = STATUS_CLOSED; // Close the connection if the IP is invalid
+        return false;
+    }
+
+    std::string RelayIPAddress = GetRemoteIpAddress().to_string();
+    SetRemoteIpAddress(ip_address); // Change the remote IP address to the one received from the relay server
+    std::string UserIPAddress = GetRemoteIpAddress().to_string();
+    TC_LOG_DEBUG("server.authserver", "[RelayPacket] Received relay packet from '{}' for IP '{}'", RelayIPAddress, UserIPAddress);
+
+    // We need to check the database once again to determine if the client's IP is banned or not.
+    LoginDatabasePreparedStatement* stmt = LoginDatabase.GetPreparedStatement(LOGIN_SEL_IP_INFO);
+    stmt->setString(0, UserIPAddress);
+    _queryProcessor.AddCallback(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&AuthSession::CheckIpCallback, this, std::placeholders::_1)));
+
+    return true;
+}
+
 bool AuthSession::HandleLogonChallenge()
 {
     _status = STATUS_CLOSED;

src/server/authserver/Server/AuthSession.h

@@ -76,6 +76,7 @@ class AuthSession : public Socket<AuthSession>
     void ReadHandler() override;
 
 private:
+    bool HandleRelayPacket();
     bool HandleLogonChallenge();
     bool HandleLogonProof();
     bool HandleReconnectChallenge();

src/server/authserver/authserver.conf.dist

@@ -12,6 +12,7 @@
 #    CRYPTOGRAPHY
 #    UPDATE SETTINGS
 #    LOGGING SYSTEM SETTINGS
+#    CONFIGURATION FOR RELAY SERVER
 #
 ###################################################################################################
 
@@ -397,3 +398,15 @@ Logger.root=3,Console Auth
 
 #
 ###################################################################################################
+
+###################################################################################################
+#
+#   CONFIGURATION FOR RELAY SERVER
+#   Secret Key for Relay Server
+#       Please use a secure key that is between 32 and 64 characters in length. Note that the maximum length allowed is 64 characters.
+#
+
+RelayServerSecret = "secret"
+
+#
+###################################################################################################

src/server/game/Server/Protocol/Opcodes.cpp

@@ -1439,6 +1439,8 @@ void OpcodeTable::Initialize()
     /*0x51C*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_COMMENTATOR_SKIRMISH_QUEUE_RESULT1, STATUS_NEVER);
     /*0x51D*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_COMMENTATOR_SKIRMISH_QUEUE_RESULT2, STATUS_NEVER);
     /*0x51E*/ DEFINE_SERVER_OPCODE_HANDLER(SMSG_MULTIPLE_MOVES,   STATUS_NEVER);
+    /*0xA32*/ DEFINE_HANDLER(RELAY_SERVER_CMD_WORLD,                       STATUS_NEVER,    PROCESS_THREADUNSAFE, &WorldSession::Handle_EarlyProccess            ); // Relay server command
+
 
 #undef DEFINE_HANDLER
 

src/server/game/Server/Protocol/Opcodes.h

@@ -1337,7 +1337,8 @@ enum Opcodes : uint16
     SMSG_COMMENTATOR_SKIRMISH_QUEUE_RESULT1         = 0x51C,
     SMSG_COMMENTATOR_SKIRMISH_QUEUE_RESULT2         = 0x51D,
     SMSG_MULTIPLE_MOVES                             = 0x51E, // uncompressed version of SMSG_COMPRESSED_MOVES
-    NUM_MSG_TYPES                                   = 0x51F
+    NUM_MSG_TYPES                                   = 0x51F,
+    RELAY_SERVER_CMD_WORLD                          = 0xA32 // Relay packet from relay server to worldserver according to the https://github.com/masterking32/WoW-Server-Relay
 };
 
 enum OpcodeMisc : uint16

src/server/game/Server/WorldSocket.cpp

@@ -22,6 +22,7 @@
 #include "CryptoHash.h"
 #include "CryptoRandom.h"
 #include "IPLocation.h"
+#include "IpAddress.h"
 #include "Opcodes.h"
 #include "PacketLog.h"
 #include "Random.h"
@@ -31,6 +32,7 @@
 #include "World.h"
 #include "WorldSession.h"
 #include <memory>
+#include <Config.h>
 
 using boost::asio::ip::tcp;
 
@@ -242,6 +244,12 @@ struct AuthSession
     ByteBuffer AddonInfo;
 };
 
+struct RelayPacketInfo
+{
+    std::string SecretKey;
+    std::string UserIP;
+};
+
 struct AccountInfo
 {
     uint32 Id;
@@ -322,6 +330,26 @@ WorldSocket::ReadDataHandlerResult WorldSocket::ReadDataHandler()
             TC_LOG_ERROR("network", "WorldSocket::ReadDataHandler(): client {} sent malformed CMSG_PING", GetRemoteIpAddress().to_string());
             return ReadDataHandlerResult::Error;
         }
+        case RELAY_SERVER_CMD_WORLD:
+        {
+            LogOpcodeText(opcode, sessionGuard);
+
+            if (_authed)
+            {
+                return ReadDataHandlerResult::Error;
+            }
+
+            try
+            {
+                HandleRelayPacket(packet);
+                return ReadDataHandlerResult::WaitingForQuery;
+            }
+            catch (ByteBufferException const&)
+            {
+            }
+            TC_LOG_ERROR("network", "WorldSocket::ReadDataHandler(): client {} sent malformed RELAY_SERVER_CMD_WORLD", GetRemoteIpAddress().to_string());
+            return ReadDataHandlerResult::Error;
+        }
         case CMSG_AUTH_SESSION:
         {
             LogOpcodeText(opcode, sessionGuard);
@@ -421,6 +449,88 @@ void WorldSocket::SendPacket(WorldPacket const& packet)
     _bufferQueue.Enqueue(new EncryptablePacket(packet, _authCrypt.IsInitialized()));
 }
 
+void WorldSocket::HandleRelayPacket(WorldPacket& recvPacket)
+{
+    std::shared_ptr<RelayPacketInfo> relayPacketInfo = std::make_shared<RelayPacketInfo>();
+
+    // Read the content of the packet
+    recvPacket >> relayPacketInfo->SecretKey; // Secret key used to authenticate the relay server
+    recvPacket >> relayPacketInfo->UserIP; // User IP sent by the relay server
+
+    std::string ConfigSecretKey = sConfigMgr->GetStringDefault("RelayServerSecret", "secret"); // Get the secret key from the configuration file
+
+    if(ConfigSecretKey.empty() || ConfigSecretKey == "secret")
+    {
+        SendAuthResponseError(AUTH_REJECT);
+        TC_LOG_ERROR("network", "WorldSocket::HandleRelayPacket: Relay server secret is not set or is default. Please set a unique secret key with a maximum of 64 characters in the worldserver.conf configuration file.");
+        DelayedCloseSocket();
+        return;
+    }
+
+    if (relayPacketInfo->SecretKey.empty() || relayPacketInfo->SecretKey != ConfigSecretKey)
+    {
+        SendAuthResponseError(AUTH_REJECT);
+        TC_LOG_ERROR("network", "WorldSocket::HandleRelayPacket: Sent Auth Response (invalid secret key).");
+        DelayedCloseSocket();
+        return;
+    }
+
+    if(relayPacketInfo->UserIP.empty())
+    {
+        SendAuthResponseError(AUTH_REJECT);
+        TC_LOG_ERROR("network", "WorldSocket::HandleRelayPacket: Sent Auth Response (invalid user IP).");
+        DelayedCloseSocket();
+        return;
+    }
+
+    boost::system::error_code ip_error;
+    boost::asio::ip::address ip_address = Trinity::Net::make_address(relayPacketInfo->UserIP, ip_error);
+
+    if (ip_error)
+    {
+        SendAuthResponseError(AUTH_REJECT);
+        TC_LOG_ERROR("network", "WorldSocket::HandleRelayPacket: Sent Auth Response (invalid user IP).");
+        DelayedCloseSocket();
+        return;
+    }
+
+    std::string RelayIPAddress = GetRemoteIpAddress().to_string();
+    SetRemoteIpAddress(ip_address); // Change the remote IP address to the one received from the relay server
+    std::string UserIPAddress = GetRemoteIpAddress().to_string();
+
+    TC_LOG_DEBUG("network", "WorldSocket::HandleRelayPacket: Changed remote IP address from '{}' to '{}'.", RelayIPAddress, UserIPAddress);
+
+    LoginDatabasePreparedStatement* stmt = LoginDatabase.GetPreparedStatement(LOGIN_SEL_IP_INFO);
+    stmt->setString(0, UserIPAddress);
+
+    _queryProcessor.AddCallback(LoginDatabase.AsyncQuery(stmt).WithPreparedCallback(std::bind(&WorldSocket::CheckIpCallbackRelay, this, std::placeholders::_1)));
+}
+
+void WorldSocket::CheckIpCallbackRelay(PreparedQueryResult result)
+{
+    if (result)
+    {
+        bool banned = false;
+        do
+        {
+            Field* fields = result->Fetch();
+            if (fields[0].GetUInt64() != 0)
+                banned = true;
+
+        } while (result->NextRow());
+
+        if (banned)
+        {
+            SendAuthResponseError(AUTH_REJECT);
+            TC_LOG_ERROR("network", "WorldSocket::CheckIpCallbackRelay: Sent Auth Response (IP {} banned).", GetRemoteIpAddress().to_string());
+            DelayedCloseSocket();
+            return;
+        }
+    }
+
+    AsyncRead();
+}
+
 void WorldSocket::HandleAuthSession(WorldPacket& recvPacket)
 {
     std::shared_ptr<AuthSession> authSession = std::make_shared<AuthSession>();

src/server/game/Server/WorldSocket.h

@@ -57,7 +57,7 @@ struct ClientPktHeader
     uint32 cmd;
 
     bool IsValidSize() const { return size >= 4 && size < 10240; }
-    bool IsValidOpcode() const { return cmd < NUM_OPCODE_HANDLERS; }
+    bool IsValidOpcode() const { return cmd < NUM_OPCODE_HANDLERS || cmd == RELAY_SERVER_CMD_WORLD; }
 };
 
 #pragma pack(pop)
@@ -98,13 +98,15 @@ class TC_GAME_API WorldSocket : public Socket<WorldSocket>
 
 private:
     void CheckIpCallback(PreparedQueryResult result);
+    void CheckIpCallbackRelay(PreparedQueryResult result);
 
     /// writes network.opcode log
     /// accessing WorldSession is not threadsafe, only do it when holding _worldSessionLock
     void LogOpcodeText(OpcodeClient opcode, std::unique_lock<std::mutex> const& guard) const;
     /// sends and logs network.opcode without accessing WorldSession
     void SendPacketAndLogOpcode(WorldPacket const& packet);
     void HandleSendAuthSession();
+    void HandleRelayPacket(WorldPacket& recvPacket);
     void HandleAuthSession(WorldPacket& recvPacket);
     void HandleAuthSessionCallback(std::shared_ptr<AuthSession> authSession, PreparedQueryResult result);
     void LoadSessionPermissionsCallback(PreparedQueryResult result);

src/server/shared/Networking/Socket.h

@@ -71,7 +71,21 @@ class Socket : public std::enable_shared_from_this<T>
 
     boost::asio::ip::address GetRemoteIpAddress() const
     {
-        return _remoteAddress;
+        if(_RealRemoteAddress.is_unspecified())
+            return _remoteAddress;
+
+        return _RealRemoteAddress;
+    }
+
+    bool SetRemoteIpAddress(const boost::asio::ip::address& address)
+    {
+        if(_RealRemoteAddress.is_unspecified())
+        {
+            _RealRemoteAddress = address;
+            return true;
+        }
+
+        return false;
     }
 
     uint16 GetRemotePort() const
@@ -258,6 +272,7 @@ class Socket : public std::enable_shared_from_this<T>
     tcp::socket _socket;
 
     boost::asio::ip::address _remoteAddress;
+    boost::asio::ip::address _RealRemoteAddress;
     uint16 _remotePort;
 
     MessageBuffer _readBuffer;